Comparison of tensile and knot security properties of surgical sutures

Sutures are classified into non-absorbable and absorbable, and mechanical properties of these materials vary by the composition. Knotting induces decrease in mechanical properties. The objective of this study was to measure the tensile and knot security properties depending on the type and caliber of sutures. Changes in properties after tensile loading were measured with absorbable sutures. Tensile properties such as maximum tensile load, elongation rate, stiffness and energy absorbed before breakage of seven kinds of surgical sutures were measured. Absorbable sutures were immersed in 37 °C Hank’s balanced salt solution up to 14 days under the tensile load of 100 g/thread, and properties were measured again. Knot was formed with surgeon’s knot method, and tensile properties were measured. Five specimens were tested for each condition. Values were analyzed with one- or two-way analysis of variance (α = 0.05). Maximum tensile load of seven sutures (caliber = 4-0) ranged from 10.0 N to 14.3 N. In non-absorbable sutures, the type of suture material influenced the tensile properties (P < 0.05). In absorbable sutures, the maximum tensile load after tensile loading decreased, which was significant in chromic catgut (CC). Knot security of seven sutures (caliber = 4-0) ranged from 8.7 N to 11.9 N. Type of non-absorbable suture influenced knot security (P < 0.05), and the synthetic monofilament materials showed a tendency to be untied easily. Since no single suture material possesses all of the requirements, proper type and caliber suture should be selected based on this study.